The present invention relates to compressor heaters and more particularly, to a bracket design and method of assembly for a compressor crankcase heater.
In closed loop refrigeration systems, a compressor pumps refrigerant through an evaporator and condenser to provide cooling or refrigeration. The refrigerant cycles through the system to return into the compressor to cycle again. When refrigerant enters the compressor, it is desirable to maintain the refrigerant in a gaseous state during its time within the compressor. Since refrigerant is heavier than lubricant, liquid refrigerant could accumulate in the compressor sump, mixing with and diluting the lubricant, thereby reducing the effectiveness of the lubrication.
The refrigerant may, in liquid form, migrate from the condenser into the compressor crankcase oil sump. During start up of the compressor, the sudden reduction in crankcase pressure may cause the refrigerant to boil, thus causing the lubricant to foam with consequent loss of lubrication to other mechanical parts of the compressor.
Even if the refrigerant is in a gaseous state when returning to the compressor, a lower temperature in the compressor could condense the refrigerant, causing the above identified problems. In order to eliminate these problems and maintain the refrigerant in a gaseous state, compressors have been provided with external heaters to maintain an elevated temperature in the compressor crankcase. Thus, any liquid refrigerant in the compressor crankcase will be vaporized.
Prior art heaters have been utilized, both internal and external. Internal heaters have previously been utilized with compressors by installing them in a heater well with a thermal mastic and a snap ring. However, the heater well is a potential leak source and the mastic is a messy production process. External heaters, mounted to the housing of the compressor, have been wrap-around designs attached with spring retention, screw clamps, adhesive strips, bolted, or welded. All of these mounting methods though are either awkward or unreliable over the expected life of the compressor and often do not provide good thermal transfer.
It is therefore a object of the present invention to provide a mounting method for a crankcase heater whereby the heater can be quickly and easily mounted.
It is therefore another object of the present invention to provide better thermal transfer from the heater to the crankcase sump.
It is further an object of the present invention to provide a heater assembly that is simple and easy to assemble.